<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=<>>, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>
<body>
    <script>
        // 强制转换 number（）
        // string，boolean-->Number(value)
        // 特点：只能识别纯数字的字符串
        // true-->1
        // false-->0
        var a = "12";
        var b = "true";
        var c = true;
        var d = false;
        console.log(Number(a));
        console.log(Number(b));
        console.log(Number(c));
        console.log(Number(d));
        

        
    </script>
</body>
</html>